As many know, I recently returned from ICCC4. It has taken me a couple of days to get back on track and I want to share over the next couple of days, some of the things I saw there.
One thing I witnessed was a story of courage and of professionalism in the face of adversity. As many know, Heartland formally invited many scientists and scholars who are AGW proponents from the other side of the aisle.
This has been done for every conference since the first one in 2008.
James M. Taylor, senior fellow for environment policy at the sponsoring Heartland Institute and the person who recruited all of the 70-plus presenters Including yours truly) at the May 16-18 conference, said this about the invitations:
“I personally and cordially invited literally dozens of high-profile scientists who disagree with our speakers, including Gavin Schmidt, James Hansen, Michael Mann, Phil Jones, William Schlesinger, and many others,” Taylor said. “I planned to give each side equal time at the conference.
Regrettably – and predictably – only two ‘warmists’ accepted my invitation to participate: Scott Denning of Colorado State University and Tam Hunt, a consultant on renewable energy and a lecturer at UC Santa Barbara’s School of Environmental Science & Management.”
All others declined, nearly all of them cordially.
Scott Denning was warmly and respectfully received, leading him to request a second opportunity to address the audience. He was granted that opportunity at the May 18 closing luncheon that I attended, where he said,
I want to thank you very much for inviting me to this conference. I have to say that I’ve learned a lot here. It was very gracious of [Heartland Institute Senior Fellow] James [Taylor] and of the organizers to bring me here. And I actually feel that it’s really too bad that more of my colleagues from the scientific community didn’t attend and haven’t in the past, and I hope that we can remedy that in the future.
Denning’s remarks, with the applause he received throughout, can be seen on the YouTube video below. It is well worth watching because it illustrates the mood of the conference well.
Many scientists missed a chance to bridge the gap, and it is sad for them that they choose to keep the wall up, rather than participate in discourse and debate. Maybe Scott Denning’s courageous example will lead to more attendees next year.
Videos of all presentations from the two-and-a-half-day conference are being posted on the Web site of the Fourth International Conference on Climate Change.
Hmmm … how does tie in with NAIS (National Animal ID program, your other favorite bogeyman)?
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They didn’t create life, they duplicated a molecule (think of it as a very long stack of punch cards) that they don’t understand and inserted it into an already, non-human-manufactured living cell. They have no more created life than the analogous punch-card stacker has written a program.
As to creating green algae that sequesters carbon, I think that’s been done.
Joel Shore,
“Are you saying that increasing greenhouse gases so that the radiative emission is now coming from levels of the atmosphere that are colder will not result in a radiative imbalance?”
Since that level is at higher altitude there is a greater emitting surface area, so more total energy could be emitted, even though at a lower temperature. If the net feedbacks to CO2 are negative instead of positive, natural variation will often dwarf the greenhouse warming contribution and the radiative imbalance may at times be negative instead of positive, even 100 years from now.
Martin Lewitt says:
Okay. So, let’s estimate the magnitude of this effect for a doubling of CO2. The average lapse rate in the troposphere is 6.5 C/km. If we assume that a doubling of CO2 produces about 3 C of warming, then that would correspond to raising the emitting level by about half a km. If you divide this by the radius of the earth (~6000km) and multiply by 2 (this factor coming from the binomial expansion (1+x)^2 is about 1 + 2x for x << 1), then you get the fractional increase in surface area, which turns out to be ~0.00017. Hence, the ~240 W/m^2 emission would be reduced by about 0.04 W/m^2. This is about a 1% reduction of the original 4 W/m^2 forcing. (And, in fact, this is probably an overestimate of the effect, since it is really probably not consistent to use the after-feedback estimate of the temperature rise but the radiative forcing of the CO2 emissions itself. I should have either used 1 C for the warming due to CO2 directly or used a higher value for the full radiative effect of a CO2 doubling, including the radiative effects due to the increase in water vapor and reduction in ice albedo.)
So, yes, there is such an effect, but it is insignificant.
That is a pretty big “IF”. As Denning explains in the talk, our current understanding of the forcings and temperature change from the last glacial maximum til now implies that the feedbacks are positive, as does other empirical evidence, as do the climate models that represent our best (albeit imperfect) understanding of the physics. And, at any rate, if you really want to show that the feedbacks are negative, then serious effort needs to be made to demonstrate this and explain how it is compatible with the paleoclimate and other data. Claiming that people who argue for the current understanding don’t understand thermodynamics and heat transfer in atmospheric physics, as BigWaveDave does, seems to be just a distraction from this.
Joel Shore says:
“Really…Could you elaborate on this? How a large a mechanism is conduction in the atmosphere? How do you understand the thermodynamics to work? In particular, let’s focus on the energy emitted to space. Are you saying that increasing greenhouse gases so that the radiative emission is now coming from levels of the atmosphere that are colder will not result in a radiative imbalance?”
Conduction is very strong at the surface, and is enhanced even further by plants. This drives convection.
The greenhouse effect in a greenhouse is due to its prevention of convection from carrying heat away. The same thing happens with earth’s greenhouse effect. Earth’s gravity prevents convection above the troposphere. Heat escapes by radiation from there.
The only prerequisite for radiation is that there is a temperature difference. There is no one radiative equilibrium temperature for Earth. Just look at IR photos from about two million miles away:
http://photojournal.jpl.nasa.gov/catalog/PIA00558
http://photojournal.jpl.nasa.gov/catalog/PIA00559
Earth’s gravity also keeps atmospheric pressure higher at lower elevations, which creates the lapse rate that keeps surface temperatures higher than top of troposphere temperatures.
Dave
Hmmmm … and what part does this play/what would the allowance be for increased direct-into-space radiation from the surface through the atmosphereic window (~10 … 15 um) result in as the ‘peak’ in the LWIR spectral curve is centered there and as we all know total emitted/radiated enegy is proportional to T ^4 and as the surface temp is assumed to be 3 deg C higher?
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It would play the role that it is calculated to play. Do you think this isn’t included in the calculations?
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BigWaveDave says:
I’m not sure what this means. The stratosphere doesn’t have convection because it is primarily heated from above (by absorption of UV by ozone) so the temperature rises with altitude, promoting stability. (Of course, gravity matters…in the sense that without gravity, you don’t have buoyancy effects, but gravity is also necessary to have a significant atmosphere at all.)
I’m not sure what this is supposed to prove. The 255 K is an average. Yes, there is variation.
Without the greenhouse gases, the surface temperature (technically, the average of T^4) would have to be the radiating temperature to maintain energy balance, which is about 255 K with the current albedo. Note that the criterion you get for the lapse rate tends to be an (approximate) upper bound…i.e., you can have lapse rates smaller than this…in fact even temperature rising with height as you do in the stratosphere. However, when the lapse rate is steeper than the criterion, then you get instability that tends to drive the lapse rate back toward this criterion.
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Joel Shore says:
May 23, 2010 at 8:15 am
Martin Lewitt says:
If the net feedbacks to CO2 are negative instead of positive, natural variation will often dwarf the greenhouse warming contribution and the radiative imbalance may at times be negative instead of positive, even 100 years from now.
That is a pretty big “IF”. As Denning explains in the talk, our current understanding of the forcings and temperature change from the last glacial maximum til now implies that the feedbacks are positive, as does other empirical evidence, as do the climate models that represent our best (albeit imperfect) understanding of the physics. And, at any rate, if you really want to show that the feedbacks are negative, then serious effort needs to be made to demonstrate this and explain how it is compatible with the paleoclimate and other data. Claiming that people who argue for the current understanding don’t understand thermodynamics and heat transfer in atmospheric physics, as BigWaveDave does, seems to be just a distraction from this.
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Sure, during periods when large amounts of reflective glaciers existed at lower latitudes. This is reinforced by the evidence of huge swings of temp at ~1500 yr intervals shown in the polar ice-cores. Once those glaciers have disappeared from all but the highest latitudes, the game changes and positive feedback is reduced to where the interglacial temps are comparatively quite stable.
One might surmise that the positive feedback during glacial periods is caused by the ice/albedo effect & not GHGs. What causes the changes from interglacial/glacial periods is the big question — ocean-current changes would be my guess. The ~800-yr time-lag of CO2 vs temps shows that it isn’t the dominate or even a significant effect IMO.
Non-answer; I’ve yet to see it described, alluded to, included as a factor.
Furthermore, are you challenging the veracity of the claim that the earth’s radiative IR spectra peaks in the vicinity of the atmospheric window? And with higher surface temperature, shows exponentially even more energy radiated thru this atmospheric window?
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So, what you are basically saying is “I think, on the basis of no evidence whatsoever, that all of the scientists in the field are doing the radiative calculations incorrectly.” One could challenge any piece of science that one didn’t like (presumably because of my ideological beliefs) in that way.
It is not exponential…It is T^4 dependence (and will pretty close to linear over the range of temperature variation that will occur on an absolute temperature scale). And, the absorption characteristics of the atmosphere are already included in all of the calculations. So, you are not adding anything new to what is already known.
beng says:
One might surmise that if one could not calculate the radiative effect of changes in GHGs to quite good accuracy and estimate the changes in radiative effects due to ice / albedo. And, it shows them to be…roughly speaking…of close to equal magnitude and of such a magnitude that the climate sensitivity is somewhere around 0.75 K per W/m^2. The only way your claim could make sense is if the ice / albedo radiative effects are being vastly underestimated.
Joel Shore says:
“Without the greenhouse gases, the surface temperature (technically, the average of T^4) would have to be the radiating temperature to maintain energy balance, which is about 255 K with the current albedo. Note that the criterion you get for the lapse rate tends to be an (approximate) upper bound…i.e., you can have lapse rates smaller than this…in fact even temperature rising with height as you do in the stratosphere. However, when the lapse rate is steeper than the criterion, then you get instability that tends to drive the lapse rate back toward this criterion.”
The point is that a greenhouse works by trapping convection, not by trapping radiation. The transfer of heat from the surface is not by radiation directly to space, it is by transfer to the atmosphere, and the atmosphere radiates to space.
BigWaveDave says:
The limitations of the analogy between an actual greenhouse and the atmospheric greenhouse effect are well-known (e.g., http://en.wikipedia.org/wiki/Greenhouse_effect ), but I am not sure what the relevance is.
Well, that is not completely true…but even if it were, I am not sure what the relevance is.
I response to:
The point is that a greenhouse works by trapping convection, not by trapping radiation.
Joel Shore says:
May 24, 2010 at 6:30 pm
“The limitations of the analogy between an actual greenhouse and the atmospheric greenhouse effect are well-known (e.g., http://en.wikipedia.org/wiki/Greenhouse_effect ), but I am not sure what the relevance is.#”
Wiki’ does say that the ghe isn’t like an actual greenhouse, but Fourier, Tyndall and Arrhenius all did think that the wacky second law violating definition Wiki gives for the ghe was the way a greenhouse actually worked.
The relevance is in that believers in the “accepted” Wiki-type definition of ghe ignore or disregard many important factors in the transfer of energy within Earth’s atmosphere, e,g. second law, mass, gravity, conduction, convection specific heat, …, which support the hypothesis that Earth’s atmosphere actually does work like an actual greenhouse.
BigWaveDave,
The earth does radiate directly into space in some parts of the spectrum. You will have difficulty explaining infrared satellite images if you doubt that. You are correct that convection and other components of the water cycle are under-represented in them models as published in Science by Wentz. None of the models were reproducing more than a half of the increase in precipitation seen in the observations in association with the recent warming. Once the heat gets higher in the troposphere via convection and release of the latent heat of the water cycle, GHGs help more efficiently radiate it into space. There is, of course, conduction in both directions between the GHGs and the less efficient radiative components of the atmosphere, O2 and N2.
Joel Shore,
The error bars in a paleo estimate of climate sensitivity such as that in Denning’s talk must necessarily be huge. I’m especially skeptical of his estimate of the increased albedo at under 4 watts, because even in the 1990s, the albedo feedback reported by Andreas Roesch just from earlier spring snow melts, amounted to over 3W/m^2 when globally and annually averaged. It just isn’t credible that ice age albedo effects due the ice sheets and desertification don’t exceed that. Denning didn’t disclose a peer review reference for his analysis, but I’d be interested in reviewing it for the sources of his estimates. I’ve yet to see any credible evidence that the net feedbacks to CO2 forcing are positive, and they need to be for AGW to be more than a just a minor warming perturbation of natural variation. Hopefully, you agree that the science isn’t decided and await new results as eagerly as I do.
BigWaveDave says:
No, they do not ignore these transfers. No, they do not ignore the Second Law and the descriptions that you read of the greenhouse effect don’t violate it. However, at the end of the day, they understand that the only way for the earth / atmosphere system to exchange heat with space is via radiation.
Martin Lewitt says:
If you guys are going to argue that somehow under-representation of convection overestimates the greenhouse warming, can one of you put some actual meat on this hypothesis. It seems to me that since what matters for the radiation back out into space is the temperature structure in the atmosphere as a result of this convection, your claim would amount to the hypothesis that because of this more efficient convection, the upper troposphere gets warmer than expected for a given amount of surface warming and is thus able to more efficiently radiate the heat back out into space. So, in other words, you seem to be suggesting that the lapse rate feedback, a negative feedback already included in the climate models, is larger in magnitude than the models believe it to be.
However, at the same time, many skeptics claim that the so-called “hot spot” predicted by the models and representing the magnification of the warming as you go up in the tropical troposphere is not there. This would then imply that the lapse rate feedback is being overestimated by the models.
I don’t see how you can have it both ways.
Martin Lewitt says:
Well, here is the IPCC discussion of estimates of climate sensitivity based on the last glacial maximum, from which you should be able to find leads into the literature on the subject: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-6-3-2.html
Joel Shore,
I was on the Working Group I draft review, so I had already reviewed the literature cited by the IPCC. Another problem with those estimates is that they cross between the ice age and the interglacial. Even if estimates of the possible error range had been done, it wouldn’t be particularly relevant to warming in an interglacial. I might go look at see if any of that is the source of his albedo estimate.
The model hot spots are not particularly hot, they are just there because the CO2 effect can’t be seen at lower altitudes in the tropics until one gets up above most of the water vapor. The disparity with the observations is in the temperature structure of troposphere column. Increased convention and transfer of heat via the water cycle, could just be washing out or masking that hot spot structure.
The models are going to have to more closely match the climate, because simplistic linear reasoning just doesn’t cut it. Models which reproduce less than half the observed precipitation increase, under-represent the surface albedo feedback by more than 3W/m^2 and reproduce less than half the amplitude of the observed response to the solar cycle, should never have been used to project or attribute the recent warming. These are all correlated errors for all the IPCC models. The correlated surface albedo feedback bias and several other diagnostic issues in the literature were known at the time of the FAR, yet the results were reported without any attempt to account for what they might imply for the projections and attribution. Using the model sensitivities and projections was the major error of the IPCC FAR.
You are actually wrong about the “hot spot”. It has nothing to do with CO2. The same magnification effect is seen in the model with solar forcing or in the models and the data for temperature variations due to ENSO. It follows from moist adiabatic lapse rate theory. Claiming that increased convection masks it makes no sense at all…and, like I said, since the negative feedback due to the lapse rate is a direct result of this magnification, its absence would mean that the lapse rate feedback is smaller in magnitude, not larger.
Joel Shore says:
“If you guys are going to argue that somehow under-representation of convection overestimates the greenhouse warming, can one of you put some actual meat on this hypothesis. It seems to me that since what matters for the radiation back out into space is the temperature structure in the atmosphere as a result of this convection, your claim would amount to the hypothesis that because of this more efficient convection, the upper troposphere gets warmer than expected for a given amount of surface warming and is thus able to more efficiently radiate the heat back out into space. So, in other words, you seem to be suggesting that the lapse rate feedback, a negative feedback already included in the climate models, is larger in magnitude than the models believe it to be.”
Consider this: Between about 20°N and 20°S latitudes, the ,Solar radiation that reaches the Earth’s surface is about 25% more than what is radiated by Earth to space, and in the two polar regions above 65°N or below 65°S, Earth’s radiation to space is about twice the incoming Solar radiation.
Joel Shore says:
“However, at the same time, many skeptics claim that the so-called “hot spot” predicted by the models and representing the magnification of the warming as you go up in the tropical troposphere is not there. This would then imply that the lapse rate feedback is being overestimated by the models.”
If the lapse rate is not properly considered as a result of gravity acting on the ideal gasses in the atmosphere, then it’s hard to say what kind of results the models will give.
Joel Shore says:
“I don’t see how you can have it both ways.”
It can’t be any harder than relying on the “not-how-a-greenhouse-works” effect.
BigWaveDave says:
Yes…And your point is? It is well-known that there is considerable transport of heat from the tropics to the polar regions both by ocean currents and atmosphere.
The lapse rate is considered in the models…and the evidence is that the magnification of temperature fluctuations as one goes up in the tropical troposphere is seen in the data on timescales of months to a few years. There is more debate on whether the multidecadal trends show this same amplification, although since both the satellite and radiosonde data are subject to artifacts that can create spurious trends over the data record, it is difficult to determine if any inconsistency really exists.
And, at any rate, it doesn’t take complicated guesswork to suggest that a model that shows more amplification than occurs in the real world would overestimate the (negative) lapse rate feedback.
I am not sure why you are so hung up on this. Analogies are always imperfect. In this case, the name for the effect was coined early on and it has persisted despite being a quite imperfect analogy to actual greenhouses. Big deal.
Joel Shore,
“You are actually wrong about the “hot spot”. It has nothing to do with CO2.”
That hasn’t really been established, but if the models demonstrate that behavior, perhaps it is because they fail to fully reproduce the difference between CO2 and water vapor. The latter is far more likely to condense, freeze, re-evaporate and precipitate. Wentz published that the models managed only one-third to one-half the increase in precipitation observed in the recent warming. However, the models did better on the water vapor increase. So the increased water vapor is apparently sitting there acting more like CO2 with a different spectrum than its dynamic water cycle self.
Martin Lewitt says:
Well, the models show the same behavior if the forcing is solar or even for the fluctuations in temperature (e.g., due to ENSO)…and, furthermore, the modelers know what sort of physics are going into the models. Roy Spencer seems to agree that the moist adiabatic lapse rate theory is the reason for the “hot spot”. So, I am not sure what additional evidence you want.
The Wentz paper is interesting but I don’t think it necessarily has anything to do with this. The Wentz paper claims to show that the models have a tendency to underpredict the rise in precipitation with warming, whether it is due to the slow underlying warming trend or due to the ENSO. However, it has been shown that there is quite good agreement between models and data on tropical tropospheric amplification for fluctuations on the monthly to yearly timescale. So, the two issues do not seem to be related.
– but the climate alarmists block and smear people like McIntyre. Eschenbach has listed their witch hunt rantings. You cannot meet halfway with evil. Sure, let’s try to not dump on those who are willing to have dialogue, but we have to be very clear on principles and emphasize the science. Doing that will result in criticism of bad science and game playing.
– and watch terminology. What does “warmist” mean? There’s a difference between someone who said in the early 1990s that climate was warming and those who blamed humans for warming (and blamed humans for cooling in the 1970s).